Homebrew PCBs

Harvey White <madyn@...> writes:
> We are talking two different things here.  if I let the paper "cool"
> or perhaps dry out on the board, it bubbles up and pulls the toner off
> the board.  This ruins the board since the toner will never go back
> again properly.

If the toner is too hot, it becomes a liquid instead of a sticky
plastic, and won't adhere the paper to the pcb.  You'll see some toner
on the paper and some on the pcb when you remove the paper in this case.
You want enough heat to make the toner stick to the pcb (the pcb needs
to be "scuffed" for mechanical adhesion) but not enough to actually melt
it.